Epicyclic gear



oct. 7, 1952 A, G, WILSON HAL 2,612,792

` EPICYCLIC GEAR 4 F1ed Jan. 2e, 1949 4 sheets-sheet 1 Oct. 7, 1952 A. G. WILSON ETAL .2,612,792

EPICYCLIC GEAR Filed Jan. 26, 1949 4 Sheets-Sheet 2 Oct. 7, 1952 A. G. wlLsoN ET AL 2,612,792

EPICYCLIC GEAR Filed Jan. 2 6, 1949 4 Sheets-Sheet 3 T22/U etpf d Effe; 012/ zll Z 61 Oct. 7, 1952 A. G. WILSON ET AL EPICYCLIC` GEAR 4 Sheets-Shea?I 4 Filed Jan. 26, 1949 Patented Oct. 7, 1952 EPICYCLIC GEAR Andrew Gordon Wilson and Albert A. Miller, Coventry, England, assignors to Self-Changing Gear Company Limited, Coventry, England Application January 26, 1949, Serial No. 72,906 In Great Britain January'ZS, 1948 This invention relates to epicyclic change speed gear units comprising sun, planet and toothed annulus gear elements, and in particular'to compounded epicyclic gears, and has forits object the provisionvof an improved two-speed gearunit suitable forfafording low-speed ratios or affording a supplemental or'emergency low-speed gear in conjunction with multi-speed compounded epicyclicgears of known type.

The invention consists in a two-speed epicyclic gear comprising a rstspeed train having a sun wheel on the input shaft, planetary' pinions carsied by a cage on the output shaft and a controllable reaction annulus, compounded with a second speed train comprising a sun wheel, a controllable reaction annulus anda planet cage carrying planetary units each of which includes a 'pair'of intermeshed planet pinions, one of which engages the annulus and the other'the' sun wheel, the arrangement being such that the planet cage and annulus of the first speed train are rotationally Vconnected with the sun and the planetcage of the second'speed train respectively, or'vic'e'versa.

The term rotationally connected? as used herein is intended to include the case where one part is integral with'another or the case where the" parts are positively coupled (such as by splines), so that the connected elements rotate asone. y

The gear according vto the invention may be combined with a multi-speed compounded epicyclic gear of known typewhereiny the firstspeed of such multi-speed gear is adopted for the rst speed ofthe two-speed gear as specified in the preceding paragraph. Furthermore, the improved gear unit may be coupled with a further epicyclic train to provide a reverse drive. y

, In the accompanying drawings:

Figures 1, 2, Band 4 arev diagrammatic views illustrating the arrangement of two forms (in. cluding a reverse gearV in Figure 4) of gear units according tothe invention.

Figurejlr is a longitudinal half-sectional diagram illustrating one form Iof two-speed gear4 uni-t according to the invention, while Figure 2 is a diagrammatic cross-section on the line 2--2 of Figure 1 lookingin the direction of the arrow.

Figure 3 is a diagrammatic longitudinal halfsectionof'a modied f orm of the improved twospeed gear unit, and Figure 4 is a diagrammatic longitudinal section illustrating the addition of a reverse train to the unit seen in Figure 3.

-Figure 5 is a longitudinal half-section showing the-construction of a four-speed gear box embodyv e 1s claims. (c1. "1i-759) ing the form of the invention diagrammatically illustrated in Figure 1 to provide a supplementary or emergency low gear, and i Figure 6 Ais a longitudinal section of a corresponding four-speed gear box (accordingtoy the.

form of Figure 1) illustrating theaddition'ofa reverse train to the emergency low train plified in Figure 5. r

' VIn carrying the invention into to one mode, as'appliedto the production of a simple two-speed unit (see Figure 1), an input' shaft kl has a sun wheel 2 meshing with planet4 pinions 3 carried by a cage 3a mounted on the output shaft 4. A toothed annulus `5 is carried by a disc member 5a provided with a sleeve extension bgrotationally mounted on the output shaft. The outer surface ofthe annulus 5' is formed as a brake drum and thev annulus is con.-

trolleol by a band brake 6 engageable with thev drum surface. Thev sun wheel 2, planets 3yan'd annulus A5 constitute the elements for one speed;`

(referred to above as the first speed) train.v

The extension sleeve 5b bears the sun vwheel of the second (lower) speed train and'this sun wheel meshes with the inner planetlgearsl'lof a set of pairs of intermeshedplanetary gears 8 and 9 (see Figure 2) of 'known type, the outer onesr 9 of which mesh with the annulus yIIJ having.

a ldisc ange la rotationallyfmounted 'on' a shoulder. 5c of the sleeve 5b. The annulusl has, an. externall brake drum surface engageable" byv twin controlling band brakes ll. {The pairs o'f intermeshed planets 8 and 9 are mounted in 'a cage 8a keyed on the output shaft 4 and rotai-E tionally supported on its inward side on the shoul` der 5c. p ,I

According to a modified form (see yFigure 3)r of the two-speed gear unit describedabove', the sun wheel-1 `of the second or lower'speedtrain for parts 5a, Illa are omittedffromthe diagram.

With both forms of two-speedunitfdescribed above, a reverse gear train may be combined. Figure 4 illustrates a reverse gear train added to a unit as shown-in Figure 3. The reverse'train for a unit illustrated in Figure 1 is 'shown in combination with the elements of that unit as appliedexemeffect according to the multi-speed compounded epicyclic gear described below with reference to Figure 5.

In Figure 4 the cage part 5c has a sleeve extension 5d on which the sun I2 of the reverse gear is mounted. The planets I3 of the reverse gear are carried on the cage I3a, the sleeve I3b of which is keyed on the output shaft 4. The reverse annulus is indicated at I4, the disc flange Ha of which is rotationally mounted on the sleeve IIb. The outer surface of the annulus is formed as a brake drum controlled by a band brake I5.

The invention will be further described with reference to the application thereof to and in combination with a four-speed compounded epicyclic gear of known type to afford an emergency or supplementary low gear. Referring to Figure 5 this multi-speed gear comprises a first speed epi-A cyclic train A the sun of which is keyed or formed upon the input shaft I and the planet cage is` ported from the input shaft and is operatively connected with the annulus of the rst gear by having the periphery of its adjacent cheek formed with teeth meshing with those of the annulus of the first gear.

The annulus of the second gear is in one with the cage of the planets of the third gear C' which is suitably rotationally supported upon a plate clutch member referred to hereinafter and the annulus for which is integral with the adjacent cheek of the planet cage of the second gear. The annulus of the second gear has an exterior brake drum surface controlled by a band brake but the annulus of the third gear is controlled only by its integral connection with the planet cage of the second gear. .A

The fourth speed isan en bloc drive through a plate clutch D, the inner plates of which are mounted upon a suitable hub on the input shaft. The outer clutch plates are carried internally of a drum having an exterior surfa-ceengageable by a controlling band brake. This clutch drum is extended in web form inwardly and has a sleeve rotationally supported on the input shaft and forms the member (referred to above) on which the planet cage of the second speed and annulus of the third speed are rotationally supported. The 4sleeve is formed with sun wheel teeth for the third speed. To the right-hand side of Figure 5 at E hydraulic piston mechanism of known kind and associated parts for operating the displaceable plates of the clutch D, are illustrated.

In carrying the invention into effect as applied to the four-speed compounded gear as above described, the first speed gear of that arrangement is adopted as the first speed train in adding the emergency low by combining a unit as described according to Figure 1 with the said four-speed gear and the same reference numerals are ernployed in Figure 5 as in Figure 1 to denote corresponding parts. (of the train A).k is rotationally supported upon thefoutput shaft! and is rotatably connected to the sun wheel 1 of the emergency low speed train F of the combination. For constructional reasons the `sun wheel member 'I is-a separate part from The sleeve 5b of the annulus 5 the sleeve 5b. The member 'I is formed with a sleeve extension 'Ia which is slid over the sleeve 5b, the two sleeves being formed with engaging splines or teeth 'Ib such that the sun wheel l is operatively coupled to the annulus 5. This sun 1 is meshed with planet pinion units in cage 8a keyed to the output shaft. The planet cage carries an appropriate series of pairs of planetary pinions 8 and 9 each unit of which comprises the planet pinion 8 meshed with the sun wheel 1 and meshed with the second planet pinion 9 meshing with the annulus I0 of the emergency low speed gear F (after the manner already described in reference to Figure 2). This annulus is formed with a brake drum controlled by band brake II and is conveniently rotationally supported upon the sleeve of the annulus 5 of the first speed of both the four-speed compounded gear and the added gear or, as shown in Figure 5, the annulus I0 is supported on a ring fitting mounted on the sleeve la which virtually forms part of the sleeve 5b.

For extending the gear shown in Figure 5 to aiiord a reverse drive, the sun wheel of the emergency gear formed on the sleeve of the annulus of the iirst speed gear is elongated or two sets of sun wheel teeth may be provided on this sleeve, one for the emergency train andv the other for the reverse drive. A planet cage for the reverse gear is keyed on the output shaft and is coupled with the planetary cage of the emergency gear. Figure 6 illustrates the provision of a reverse gear in a four-speed gear box having an emergency low. The arrangement shown in this figure is equivalent to that illustrated in Figure 5 with regard to the trains A, B, C and F, differing only in constructional modifications and the omission of certain obvious accessories such, for instance. as the band brakes.

In Figure 6 the sun wheel member I is coupled by splines 'Ib to sleeve 5b of vthe annulus of train A and is extended longitudinally to provide sun teeth Ic for the emergency low train F and the reverse train G. In this instance the planet pinions 8, 9 are each exemplified as double pinions and` their cage 8a. is rotationally supported at its periphery in a ring member I6 positioned between the annulus I0 of the train F and the annulusl I4 of the train G. The planets I3 of the reverse train G are mounted in cage I3a keyed on the output shaft 4 at I3b and the inward ring of said cage is rotationally in `one with the cage of train F by means of a toothed coupling with annular teeth on the adjacent cage member la, as at I3c. The annulus of the reverse gear G is designated I4 and the part Ida of such is rotationally supported on -the sleeve extension I3 b of the cage I 3a as in the case of the reverse gear depicted in Figure 4.

In Figure 6 the annuli of gears A and of trains F and Gl are formed externally as drums and are controlled by band brakes (not shown) after the manner illustrated in Figure 5.

The reverse gear for the modified emergency gear of Figure 3 has already been described above with reference to Figure 4.

In combining a' gear unit according to the modification shown in Figure 3, with a fourspeed compounded epicyclic gear as referred to 1n Figure 5, no separate drawing is required to illustratesuch arrangement as reference tofthe.

two Figures 3 and 5 with the following description will make .the combination clear. The 'annulus 5 of the train A, instead of being rotationally connected with the sun wheel of the emerover the output shaft.v n

i Asecond speed train, and rfor affording a reverse genc'y low train, is integral with or rotationally connected to the cage carrying intermeshed planets (as 8 and 9) and the sun wheell 1 is on the output shaft 4 on Whi'chithe annulus (as i0 and disc'member l0a,'Eigure' 35 of the emergency low train is rotationally supported.v

' In order toadd a reverse gear to the combination described in the vpreceding paragraph, an

yarrangement as illustrated in? Figure 4 is employed. Thus the sun wheel'o'f the reverse train will be rotationally supported on the output shaft '4' and rotationally Aconnected with the planet cage of theemergency low gear vand the annulus of a train A, while the planets (asl of Figure 4) are in a cage vieyed on the output shaftwith the 'annulusl (asQHi) rotationally supported over a sleeve, such as l 3b on the output shaft. We'claixn':ll n

1'. An'epicyclic two-,speed gear unit for affording an exceptionally low forward speed ratio or an emergency low, gear, including a first speed train having a sun Wheel on the input shaft, planetary pinions carried by a cageon the output shaft, and a controllable reaction annulus, said train being compounded with a second and lower speed forward train comprising 'three elements namely, a controllable reaction annulus, a sun Wheel, and a planet cage carrying planetary each `of which includes al pair of intermeshed planet pinions, the arrangement being such that one of the latter two elements isrotationally connected to the reaction annulus; of the rst speedtrain and the other `elementis rotationally connected to the planetcage ofthe iirst speedtrain.

2. An epicyclic gear unit as claimed in claim l wherein the sun wheel of the said second speed ltrain, is rotationally connected 4to said first speed train s annulus which latten is rotatably.: mounted 3. An epicyclic gear unit as claimed in claim 1 wherein the sun wheel of the said second speed train is rotationally connected to said rst speed train annulus which latter is rotatably mounted on .the output shaft, and the planet cage of the second speed train is keyed on the output shaft and the second speed train annulus is rotatably mounted on a sleeve which latter is rotationally connected with the first speed train annulus and with the sun wheel of the second speed train.

, 4. An epicyclic gear unit as claimed in claim 1 Awherein the sun wheel of the second speed train is rotationally connected to the planet cage of the iirst speed train and .the planet cage of the second speed train is rotationally connected with the annulus of the first speed train and is also rotatably mounted over the output shaft.

5. An epicyclic gear unit as claimed in claim 1 wherein the sun Wheel of the second speed train is rotationally connected to the planet cage of the first speed train and .the planet cage of the second speed train is rotationally connected with the annulus of the first speed train and is also rotatably mounted over the output shaft, and the annulus of the second speed train is also mounted over the output shaft.

6. An epicyclic two speed and reverse gear having a gear unit as claimed in claim 1 wherein the sun wheel of the said second speed train is rotationally connected to the planet cage of said first speed train and the annulus of the latter is rotatably connected to lthe planet cage of the including a third train comprising a sun wheel rotationally connected to the annulus of the rst 6 ltrain',fplanets, a planet cage keyed'on the output shaft and `rotationally'/connected tothe planet cage -of the vfirst train, areaction annulusrotatably mounted on the output shaft, and-"control means'for said reaction annulus. y

7.- An epicyclic two-speed and `reversegeajr having a gear unit asclaimed in claiml llwherein the sun wheel of the second speed'train is rota. tionally Aconnected to the planet cage of the first speedl train/1 andthe planet cage 'ofthe second speed -train is rotationally connected with the ari'- nulus ofthe first speed trainan'd is also rotatably mounted over the output shaft, and including a third train foraiordin'g a reverse comprising a sunv wheel rotationally connected to the planet cage of' the second-v speed train,fplanets, Aa planet cage" keyed on the output shaft,V va reaction/ane nulus rotatably mounted onthe output-shaft, and control'means for said reaction annulus.

8. A' multi-speed compounded epicycli'c'gear including a first speed gear unit comprising'a sun'wheel on the input shaft', planets, a vplanet cage' on the outputl shaft, and a vcc'introlledreac' tion"annulus rotatably mounted on the output shaft, andan emergency low gear Vunit affording an exceptionally'jlow speed forward ratio combined with said rst speed gear unit' and! com-- prising a sun wheel rotationally" connected with the annulus of rthe first speed 'gear r'iitf'a controlled 'annulus rotatablymounted over vthe voutput shaft, a planet cage in driving' connection with the 4output shaftan'd oarryingffplanetary pinion. units each of which-includesfa 'pair of intermeshed planetpinions, one of said pinions engaging'the low gear l offfsaid: pinions engaging the ,lo-wi gearunit' -sun vxheelllwx"k I 'i 9. AA multi-'speed compounded epicyclic gear including ra'i'lrst speed gear unit comprising la' sun vwheel on the *input shaft, "planets, fa planet cage onfthf output shaft,` and a controlled reaction annulus rotatably mounted on the output shaft, an emergency low gear unit affording an 4 exceptionally low speed forward ratio combined with said first speed gear unit and comprising a sun wheel rotationally connected with the annulus of the first speed gear, a controlled annulus rotatably mounted over the output shaft, a planet cage in driving connection with the output shaft and carrying planetary pinion units each of which includes a pair of intermeshed planet pinions, one of said pinions engaging the low gear unit annulus and the other of said pinions engaging the low gear unit sun wheel, and including a reverse gear train comprising a sun wheel rotationallyconnected with the sun wheel of the emergency low train, planets, a

planet cage included in the driving connectionk of the planet cage of the emergency low gear unit, and a controlled annulus rotatably mounted over the output shaft.

l0. In a multi-speed compounded epicyclic gear, having a rst speed gear comprising a sun wheel on the input shaft, planets, a planet cage on the output shaft and a controllable reaction annulus rotatably mounted on the output shaft, the provision of a supplementary and exceptionally low gear combined with said first speed gear and comprising a sun wheel on the output shaft and rotationally connected with the planet cage of said first speed gear, intermeshed planet pinion pairs and planet cage rotationally connected with the annulus of the rst speed gear'y unit annulus 'and the other which is also rotatably mounted the controllable annulus of the said supplementary low gear.

11. In a multi-speed compounded epicyclic gear as claimed in claim 10, the provision of a reverse gear train comprising a sun wheel mounted in driving relation with the output shaft and in driving relation with the planet cage of the said supplementary low gear and with the reaction annulus of said ilrst speed gear, planets in a planet cage also in driving relation with the output shaft, and a controllable reaction annulus rotatably mounted over the output shaft.

12.A A compounded epicyclic gear for affording an exceptionally low forward speed ratio or an emergency low forward gear, including a first speed train having a sun wheel on the input shaft, planetary pinions carried by a cage on the output shaft, and a controllable reaction annulus, and a second and lower speed forward train comprising three elements, namely a controllable reaction annulus, a sun wheel, and a planet cage carrying planetary units each of which includes a pair of intermeshed planet pinions, the arrangement being such that one of the latter two elements is rotationally connected to the reaction annulus of the ilrst speed train and the other element is rotationally connected to the planet cage of the rst speed train.

13. A compounded epicyclic gear according to claim 12, wherein the sun wheel of the said second speed train is rotationally connected to said ilrst speed train annulus which latter is rotationally mounted over the output shaft.

14. A compounded epicyclic gear according to claim 12, wherein the sun wheel of said second speed train is rotationally connected to said first speed train annulus which latter is rotatably mounted on the output shaft, and the planet cage of the second speed train is keyed on the output shaft and the second speedr train annulus is rotatably mounted on a sleeve which latter is ro- 8 tationally connected with the first speed train annulus and with the sun wheel of the second speed train.

15. A compounded epicyclic gear according to claim 12, wherein the sun wheel of the second speed train is rotationally connected to the planet cage of the first ,speed train and the planet cage of the second speed train is rotationally connected with the annulus of the rst speed train and is also rotatably mounted over the output shaft.

16. A compounded epicyclic gear according to claim 12, wherein the sun wheel of the second speed train is rotationally connected to the planet cage of the rst speed train and the planet cage of the second speed train is rotationally connected with the annulus of the iirst speed train and is also rotatably mounted over the output shaft, and the annulus of the second speed train is also mounted over the output shaft.

- A. GORDON WILSON. A. A. MILLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Date 

